logfs: commit reservations under space pressure
Ensures we only return -ENOSPC when there really is no space.
Signed-off-by: Joern Engel <joern@logfs.org>
diff --git a/fs/logfs/file.c b/fs/logfs/file.c
index 370f367..bf9b1cf 100644
--- a/fs/logfs/file.c
+++ b/fs/logfs/file.c
@@ -161,7 +161,17 @@
static void logfs_invalidatepage(struct page *page, unsigned long offset)
{
- move_page_to_btree(page);
+ struct logfs_block *block = logfs_block(page);
+
+ if (block->reserved_bytes) {
+ struct super_block *sb = page->mapping->host->i_sb;
+ struct logfs_super *super = logfs_super(sb);
+
+ super->s_dirty_pages -= block->reserved_bytes;
+ block->ops->free_block(sb, block);
+ BUG_ON(bitmap_weight(block->alias_map, LOGFS_BLOCK_FACTOR));
+ } else
+ move_page_to_btree(page);
BUG_ON(PagePrivate(page) || page->private);
}
diff --git a/fs/logfs/logfs.h b/fs/logfs/logfs.h
index 32bf556..26a9458 100644
--- a/fs/logfs/logfs.h
+++ b/fs/logfs/logfs.h
@@ -394,6 +394,7 @@
int s_lock_count;
mempool_t *s_block_pool; /* struct logfs_block pool */
mempool_t *s_shadow_pool; /* struct logfs_shadow pool */
+ struct list_head s_writeback_list; /* writeback pages */
/*
* Space accounting:
* - s_used_bytes specifies space used to store valid data objects.
diff --git a/fs/logfs/readwrite.c b/fs/logfs/readwrite.c
index e37cee3..0718d11 100644
--- a/fs/logfs/readwrite.c
+++ b/fs/logfs/readwrite.c
@@ -1095,17 +1095,25 @@
int get_page_reserve(struct inode *inode, struct page *page)
{
struct logfs_super *super = logfs_super(inode->i_sb);
+ struct logfs_block *block = logfs_block(page);
int ret;
- if (logfs_block(page) && logfs_block(page)->reserved_bytes)
+ if (block && block->reserved_bytes)
return 0;
logfs_get_wblocks(inode->i_sb, page, WF_LOCK);
- ret = logfs_reserve_bytes(inode, 6 * LOGFS_MAX_OBJECTSIZE);
+ while ((ret = logfs_reserve_bytes(inode, 6 * LOGFS_MAX_OBJECTSIZE)) &&
+ !list_empty(&super->s_writeback_list)) {
+ block = list_entry(super->s_writeback_list.next,
+ struct logfs_block, alias_list);
+ block->ops->write_block(block);
+ }
if (!ret) {
alloc_data_block(inode, page);
- logfs_block(page)->reserved_bytes += 6 * LOGFS_MAX_OBJECTSIZE;
+ block = logfs_block(page);
+ block->reserved_bytes += 6 * LOGFS_MAX_OBJECTSIZE;
super->s_dirty_pages += 6 * LOGFS_MAX_OBJECTSIZE;
+ list_move_tail(&block->alias_list, &super->s_writeback_list);
}
logfs_put_wblocks(inode->i_sb, page, WF_LOCK);
return ret;
@@ -2251,6 +2259,7 @@
int min_fill = 3 * super->s_no_blocks;
INIT_LIST_HEAD(&super->s_object_alias);
+ INIT_LIST_HEAD(&super->s_writeback_list);
mutex_init(&super->s_write_mutex);
super->s_block_pool = mempool_create_kmalloc_pool(min_fill,
sizeof(struct logfs_block));